team-10/venv/Lib/site-packages/transformers/models/pix2struct/modeling_pix2struct.py
2025-08-02 02:00:33 +02:00

1609 lines
70 KiB
Python

# coding=utf-8
# Copyright 2023 The HuggingFace Inc. & Google team. All rights reserved.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
"""Pix2Struct modeling file"""
import math
from typing import Optional, Union
import torch
import torch.utils.checkpoint
from torch import nn
from ...activations import ACT2FN
from ...cache_utils import Cache, DynamicCache, EncoderDecoderCache
from ...generation import GenerationMixin
from ...modeling_attn_mask_utils import AttentionMaskConverter
from ...modeling_layers import GradientCheckpointingLayer
from ...modeling_outputs import (
BaseModelOutput,
BaseModelOutputWithPooling,
CausalLMOutputWithCrossAttentions,
Seq2SeqLMOutput,
Seq2SeqModelOutput,
)
from ...modeling_utils import PreTrainedModel
from ...utils import (
DUMMY_INPUTS,
DUMMY_MASK,
auto_docstring,
is_torch_flex_attn_available,
is_torch_fx_proxy,
is_torchdynamo_compiling,
logging,
)
from .configuration_pix2struct import Pix2StructConfig, Pix2StructTextConfig, Pix2StructVisionConfig
if is_torch_flex_attn_available():
from torch.nn.attention.flex_attention import BlockMask
from ...integrations.flex_attention import make_flex_block_causal_mask
logger = logging.get_logger(__name__)
# General docstring
# Adapted from transformers.models.t5.modeling_t5.T5LayerNorm with T5->Pix2Struct
class Pix2StructLayerNorm(nn.Module):
def __init__(self, hidden_size, eps=1e-6):
"""
Construct a layernorm module in the T5 style. No bias and no subtraction of mean.
"""
super().__init__()
self.weight = nn.Parameter(torch.ones(hidden_size))
self.variance_epsilon = eps
def forward(self, hidden_states):
# T5 uses a layer_norm which only scales and doesn't shift, which is also known as Root Mean
# Square Layer Normalization https://huggingface.co/papers/1910.07467 thus variance is calculated
# w/o mean and there is no bias. Additionally we want to make sure that the accumulation for
# half-precision inputs is done in fp32
variance = hidden_states.to(torch.float32).pow(2).mean(-1, keepdim=True)
hidden_states = hidden_states * torch.rsqrt(variance + self.variance_epsilon)
# convert into half-precision if necessary
if self.weight.dtype in [torch.float16, torch.bfloat16]:
hidden_states = hidden_states.to(self.weight.dtype)
return self.weight * hidden_states
try:
from apex.normalization import FusedRMSNorm
Pix2StructLayerNorm = FusedRMSNorm # noqa
logger.info("Discovered apex.normalization.FusedRMSNorm - will use it instead of Pix2StructLayerNorm")
except ImportError:
# using the normal Pix2StructLayerNorm
pass
except Exception:
logger.warning("Discovered apex but it failed to load, falling back to Pix2StructLayerNorm")
pass
class Pix2StructVisionEmbeddings(nn.Module):
r"""
Construct the embeddings from patch. In `Pix2Struct` the input is different from classic Vision-transformer models.
Here the input is a sequence of `seq_len` flattened patches that also combines padding patches (tokens). Each patch
is represented by a vector of `hidden_size` values.
"""
def __init__(self, config: Pix2StructConfig) -> None:
super().__init__()
self.patch_projection = nn.Linear(config.patch_embed_hidden_size, config.hidden_size)
self.row_embedder = nn.Embedding(config.seq_len, config.hidden_size)
self.column_embedder = nn.Embedding(config.seq_len, config.hidden_size)
self.dropout = nn.Dropout(config.dropout_rate)
def forward(self, flattened_patches: torch.Tensor) -> torch.Tensor:
# the row and column indices are stored in the first and second position of the flattened_patches
# flattened_patches: `batch_size`, `seq_len`, `hidden_size` + 2
row_indices = flattened_patches[:, :, 0].long()
col_indices = flattened_patches[:, :, 1].long()
flattened_patches = flattened_patches[:, :, 2:]
embeddings = self.patch_projection(flattened_patches)
row_embeddings = self.row_embedder(row_indices)
col_embeddings = self.column_embedder(col_indices)
# sum all embeddings together
embeddings = embeddings + row_embeddings + col_embeddings
embeddings = self.dropout(embeddings)
return embeddings
class Pix2StructVisionAttention(nn.Module):
def __init__(self, config):
super().__init__()
self.hidden_size = config.hidden_size
self.key_value_proj_dim = config.d_kv
self.n_heads = config.num_attention_heads
self.dropout = config.attention_dropout
self.inner_dim = self.n_heads * self.key_value_proj_dim
# Mesh TensorFlow initialization to avoid scaling before softmax
self.query = nn.Linear(self.hidden_size, self.inner_dim, bias=False)
self.key = nn.Linear(self.hidden_size, self.inner_dim, bias=False)
self.value = nn.Linear(self.hidden_size, self.inner_dim, bias=False)
self.output = nn.Linear(self.inner_dim, self.hidden_size, bias=False)
self.gradient_checkpointing = False
def forward(
self,
hidden_states,
attention_mask=None,
position_bias=None,
layer_head_mask=None,
output_attentions=False,
):
"""
Self-attention block
"""
# Input is (batch_size, seq_length, dim)
# Mask is (batch_size, key_length) (non-causal) or (batch_size, key_length, key_length)
# past_key_value[0] is (batch_size, n_heads, q_len - 1, dim_per_head)
batch_size, seq_length = hidden_states.shape[:2]
def to_projection_shape(states):
"""projection"""
return states.contiguous().view(batch_size, -1, self.n_heads, self.key_value_proj_dim).transpose(1, 2)
# get query states
# (batch_size, n_heads, seq_length, dim_per_head)
query_states = to_projection_shape(self.query(hidden_states))
# get key/value states
key_states = to_projection_shape(self.key(hidden_states))
value_states = to_projection_shape(self.value(hidden_states))
# compute scores
# equivalent of torch.einsum("bnqd,bnkd->bnqk", query_states, key_states), compatible with onnx op>9
scores = torch.matmul(query_states, key_states.transpose(3, 2))
if position_bias is None:
position_bias = torch.zeros(
(1, self.n_heads, seq_length, seq_length), device=scores.device, dtype=scores.dtype
)
if self.gradient_checkpointing and self.training:
position_bias.requires_grad = True
if attention_mask.dim() == 2:
position_bias = position_bias + attention_mask[:, None, None, :].to(position_bias.device)
elif attention_mask is not None:
# (batch_size, n_heads, seq_length, key_length)
position_bias = position_bias + attention_mask.to(position_bias.device)
elif not is_torchdynamo_compiling():
attention_mask = torch.ones(
(batch_size, seq_length), device=position_bias.device, dtype=position_bias.dtype
)
position_bias = position_bias + attention_mask.to(position_bias.device)
position_bias = 1 - position_bias
position_bias_masked = position_bias.masked_fill(position_bias == 1, torch.finfo(scores.dtype).min)
scores += position_bias_masked
scores = torch.max(scores, torch.tensor(torch.finfo(scores.dtype).min))
# (batch_size, n_heads, seq_length, key_length)
attn_weights = nn.functional.softmax(scores, dim=-1, dtype=torch.float32).type_as(scores)
# (batch_size, n_heads, seq_length, key_length)
attn_weights = nn.functional.dropout(attn_weights, p=self.dropout, training=self.training)
# Mask heads if we want to
if layer_head_mask is not None:
attn_weights = attn_weights * layer_head_mask
attn_output = torch.matmul(attn_weights, value_states)
# (batch_size, seq_length, dim)
attn_output = attn_output.transpose(1, 2).contiguous().view(batch_size, -1, self.inner_dim)
attn_output = self.output(attn_output)
outputs = (attn_output,) + (position_bias,)
if output_attentions:
outputs = outputs + (attn_weights,)
return outputs
# Copied from transformers.models.t5.modeling_t5.T5DenseGatedActDense with T5DenseGatedActDense->Pix2StructVisionMlp,T5Config->Pix2StructVisionConfig,config.d_model->config.hidden_size,dropout_rate->dropout_rate
class Pix2StructVisionMlp(nn.Module):
def __init__(self, config: Pix2StructVisionConfig):
super().__init__()
self.wi_0 = nn.Linear(config.hidden_size, config.d_ff, bias=False)
self.wi_1 = nn.Linear(config.hidden_size, config.d_ff, bias=False)
self.wo = nn.Linear(config.d_ff, config.hidden_size, bias=False)
self.dropout = nn.Dropout(config.dropout_rate)
self.act = ACT2FN[config.dense_act_fn]
def forward(self, hidden_states):
hidden_gelu = self.act(self.wi_0(hidden_states))
hidden_linear = self.wi_1(hidden_states)
hidden_states = hidden_gelu * hidden_linear
hidden_states = self.dropout(hidden_states)
# To make 8bit quantization work for google/flan-t5-xxl, self.wo is kept in float32.
# See https://github.com/huggingface/transformers/issues/20287
# we also make sure the weights are not in `int8` in case users will force `_keep_in_fp32_modules` to be `None``
if (
isinstance(self.wo.weight, torch.Tensor)
and hidden_states.dtype != self.wo.weight.dtype
and self.wo.weight.dtype != torch.int8
):
hidden_states = hidden_states.to(self.wo.weight.dtype)
hidden_states = self.wo(hidden_states)
return hidden_states
class Pix2StructVisionLayer(GradientCheckpointingLayer):
def __init__(self, config: Pix2StructConfig) -> None:
super().__init__()
self.chunk_size_feed_forward = config.chunk_size_feed_forward
self.seq_len_dim = 1
self.attention = Pix2StructVisionAttention(config)
self.mlp = Pix2StructVisionMlp(config)
self.pre_mlp_layer_norm = Pix2StructLayerNorm(config.hidden_size, eps=config.layer_norm_eps)
self.pre_attention_layer_norm = Pix2StructLayerNorm(config.hidden_size, eps=config.layer_norm_eps)
def forward(
self,
hidden_states: torch.Tensor,
attention_mask: Optional[torch.Tensor] = None,
head_mask: Optional[torch.Tensor] = None,
output_attentions: bool = False,
) -> Union[tuple[torch.Tensor, torch.Tensor], tuple[torch.Tensor]]:
residual = hidden_states
# in Pix2StructVision, layernorm is applied before self-attention
hidden_states = self.pre_attention_layer_norm(hidden_states)
self_attention_outputs = self.attention(
hidden_states,
attention_mask=attention_mask,
layer_head_mask=head_mask,
output_attentions=output_attentions,
)
attention_output = self_attention_outputs[0]
outputs = self_attention_outputs[1:] # add self attentions if we output attention weights
# first residual connection
hidden_states = attention_output + residual
# in Pix2StructVision, layernorm is also applied after self-attention
layer_output = self.pre_mlp_layer_norm(hidden_states)
layer_output = self.mlp(layer_output) + hidden_states # second residual connection
outputs = (layer_output,) + outputs
return outputs
class Pix2StructVisionEncoder(nn.Module):
def __init__(self, config: Pix2StructConfig) -> None:
super().__init__()
self.config = config
self.layer = nn.ModuleList([Pix2StructVisionLayer(config) for _ in range(config.num_hidden_layers)])
self.gradient_checkpointing = False
def forward(
self,
hidden_states: torch.Tensor,
attention_mask: Optional[torch.Tensor] = None,
head_mask: Optional[torch.Tensor] = None,
output_attentions: bool = False,
output_hidden_states: bool = False,
return_dict: bool = True,
) -> Union[tuple, BaseModelOutput]:
all_hidden_states = () if output_hidden_states else None
all_self_attentions = () if output_attentions else None
for i, layer_module in enumerate(self.layer):
if output_hidden_states:
all_hidden_states = all_hidden_states + (hidden_states,)
layer_head_mask = head_mask[i] if head_mask is not None else None
layer_outputs = layer_module(hidden_states, attention_mask, layer_head_mask, output_attentions)
hidden_states = layer_outputs[0]
if output_attentions:
all_self_attentions = all_self_attentions + (layer_outputs[1],)
if output_hidden_states:
all_hidden_states = all_hidden_states + (hidden_states,)
if not return_dict:
return tuple(v for v in [hidden_states, all_hidden_states, all_self_attentions] if v is not None)
return BaseModelOutput(
last_hidden_state=hidden_states,
hidden_states=all_hidden_states,
attentions=all_self_attentions,
)
@auto_docstring
class Pix2StructPreTrainedModel(PreTrainedModel):
config: Pix2StructConfig
_can_compile_fullgraph = False
@property
def dummy_inputs(self):
input_ids = torch.tensor(DUMMY_INPUTS)
input_mask = torch.tensor(DUMMY_MASK)
dummy_inputs = {
"decoder_input_ids": input_ids,
"input_ids": input_ids,
"decoder_attention_mask": input_mask,
}
return dummy_inputs
def _init_weights(self, module):
"""Initialize the weights"""
factor = self.config.initializer_factor # Used for testing weights initialization
if isinstance(module, Pix2StructLayerNorm):
module.weight.data.fill_(factor * 1.0)
elif isinstance(module, Pix2StructTextDenseGatedActDense):
hidden_size = (
self.config.text_config.hidden_size
if isinstance(self.config, Pix2StructConfig)
else self.config.hidden_size
)
d_ff = self.config.text_config.d_ff if isinstance(self.config, Pix2StructConfig) else self.config.d_ff
module.wi_0.weight.data.normal_(mean=0.0, std=factor * ((hidden_size) ** -0.5))
if hasattr(module.wi_0, "bias") and module.wi_0.bias is not None:
module.wi_0.bias.data.zero_()
module.wi_1.weight.data.normal_(mean=0.0, std=factor * ((hidden_size) ** -0.5))
if hasattr(module.wi_1, "bias") and module.wi_1.bias is not None:
module.wi_1.bias.data.zero_()
module.wo.weight.data.normal_(mean=0.0, std=factor * ((d_ff) ** -0.5))
if hasattr(module.wo, "bias") and module.wo.bias is not None:
module.wo.bias.data.zero_()
elif isinstance(module, Pix2StructTextAttention):
# Mesh TensorFlow attention initialization to avoid scaling before softmax
# See https://github.com/tensorflow/mesh/blob/fa19d69eafc9a482aff0b59ddd96b025c0cb207d/mesh_tensorflow/transformer/attention.py#L136
hidden_size = (
self.config.text_config.hidden_size
if isinstance(self.config, Pix2StructConfig)
else self.config.hidden_size
)
key_value_proj_dim = (
self.config.text_config.d_kv if isinstance(self.config, Pix2StructConfig) else self.config.hidden_size
)
n_heads = (
self.config.text_config.num_heads
if isinstance(self.config, Pix2StructConfig)
else self.config.num_heads
)
module.query.weight.data.normal_(mean=0.0, std=factor * ((hidden_size * key_value_proj_dim) ** -0.5))
module.key.weight.data.normal_(mean=0.0, std=factor * (hidden_size**-0.5))
module.value.weight.data.normal_(mean=0.0, std=factor * (hidden_size**-0.5))
module.output.weight.data.normal_(mean=0.0, std=factor * ((n_heads * key_value_proj_dim) ** -0.5))
if module.has_relative_attention_bias:
module.relative_attention_bias.weight.data.normal_(mean=0.0, std=factor * ((hidden_size) ** -0.5))
elif isinstance(module, nn.Embedding):
hidden_size = (
self.config.text_config.hidden_size
if isinstance(self.config, Pix2StructConfig)
else self.config.hidden_size
)
module.weight.data.normal_(mean=0.0, std=factor * ((hidden_size) ** -0.5))
if module.padding_idx is not None:
module.weight.data[module.padding_idx].zero_()
elif isinstance(module, Pix2StructTextModel):
hidden_size = (
self.config.text_config.hidden_size
if isinstance(self.config, Pix2StructConfig)
else self.config.hidden_size
)
module.lm_head.weight.data.normal_(mean=0.0, std=factor * ((hidden_size) ** -0.5))
elif isinstance(module, (nn.Linear, nn.Conv2d)):
# Upcast the input in `fp32` and cast it back to desired `dtype` to avoid
# `trunc_normal_cpu` not implemented in `half` issues
module.weight.data = nn.init.trunc_normal_(
module.weight.data.to(torch.float32), mean=0.0, std=self.config.initializer_range
).to(module.weight.dtype)
if module.bias is not None:
module.bias.data.zero_()
elif isinstance(module, Pix2StructLayerNorm):
if module.weight is not None:
module.weight.data.fill_(1.0)
elif isinstance(module, nn.Embedding):
module.weight.data.normal_(mean=0.0, std=self.config.initializer_range)
if module.padding_idx is not None:
module.weight.data[module.padding_idx].zero_()
# Copied from transformers.models.t5.modeling_t5.T5PreTrainedModel._shift_right with T5->Pix2Struct
def _shift_right(self, input_ids):
decoder_start_token_id = self.config.decoder_start_token_id
pad_token_id = self.config.pad_token_id
if decoder_start_token_id is None:
raise ValueError(
"self.model.config.decoder_start_token_id has to be defined. In Pix2Struct it is usually set to the pad_token_id. "
"See Pix2Struct docs for more information."
)
# shift inputs to the right
if is_torch_fx_proxy(input_ids):
# Item assignment is not supported natively for proxies.
shifted_input_ids = torch.full(input_ids.shape[:-1] + (1,), decoder_start_token_id)
shifted_input_ids = torch.cat([shifted_input_ids, input_ids[..., :-1]], dim=-1)
else:
shifted_input_ids = input_ids.new_zeros(input_ids.shape)
shifted_input_ids[..., 1:] = input_ids[..., :-1].clone()
shifted_input_ids[..., 0] = decoder_start_token_id
if pad_token_id is None:
raise ValueError("self.model.config.pad_token_id has to be defined.")
# replace possible -100 values in labels by `pad_token_id`
shifted_input_ids.masked_fill_(shifted_input_ids == -100, pad_token_id)
return shifted_input_ids
@auto_docstring
class Pix2StructVisionModel(Pix2StructPreTrainedModel):
config: Pix2StructVisionConfig
main_input_name = "flattened_patches"
supports_gradient_checkpointing = True
_no_split_modules = ["Pix2StructVisionLayer"]
def __init__(self, config: Pix2StructConfig):
super().__init__(config)
self.config = config
self.embeddings = Pix2StructVisionEmbeddings(config)
self.encoder = Pix2StructVisionEncoder(config)
self.layernorm = Pix2StructLayerNorm(config.hidden_size, eps=config.layer_norm_eps)
# Initialize weights and apply final processing
self.post_init()
def get_input_embeddings(self):
return self.embeddings.patch_projection
def _prune_heads(self, heads_to_prune: dict[int, list[int]]) -> None:
"""
Prunes heads of the model. heads_to_prune: dict of {layer_num: list of heads to prune in this layer} See base
class PreTrainedModel
"""
for layer, heads in heads_to_prune.items():
self.encoder.layer[layer].attention.prune_heads(heads)
@auto_docstring
def forward(
self,
flattened_patches: Optional[torch.Tensor] = None,
attention_mask: Optional[torch.Tensor] = None,
head_mask: Optional[torch.Tensor] = None,
output_attentions: Optional[bool] = None,
output_hidden_states: Optional[bool] = None,
return_dict: Optional[bool] = None,
) -> Union[tuple, BaseModelOutputWithPooling]:
r"""
flattened_patches (`torch.FloatTensor` of shape `(batch_size, sequence_length, num_channels x patch_height x patch_width)`):
Flattened and padded pixel values. These values can be obtained using [`AutoImageProcessor`]. See
[`Pix2StructVisionImageProcessor.__call__`] for details. Check the [original
paper](https://huggingface.co/papers/2210.03347) (figure 5) for more details.
Example:
```python
>>> import requests
>>> from PIL import Image
>>> from transformers import AutoProcessor, Pix2StructVisionModel
>>> image_processor = AutoProcessor.from_pretrained("google/pix2struct-textcaps-base")
>>> model = Pix2StructVisionModel.from_pretrained("google/pix2struct-textcaps-base")
>>> url = "https://www.ilankelman.org/stopsigns/australia.jpg"
>>> image = Image.open(requests.get(url, stream=True).raw)
>>> inputs = image_processor(images=image, return_tensors="pt")
>>> with torch.no_grad():
... outputs = model(**inputs)
>>> last_hidden_states = outputs.last_hidden_state
>>> list(last_hidden_states.shape)
[1, 2048, 768]
```
"""
output_attentions = output_attentions if output_attentions is not None else self.config.output_attentions
output_hidden_states = (
output_hidden_states if output_hidden_states is not None else self.config.output_hidden_states
)
return_dict = return_dict if return_dict is not None else self.config.use_return_dict
if flattened_patches is None:
raise ValueError("You have to specify flattened_patches")
if attention_mask is None:
# check where `flattened_patches` is not 0
attention_mask = (flattened_patches.sum(dim=-1) != 0).float()
# Prepare head mask if needed
# 1.0 in head_mask indicate we keep the head
# attention_probs has shape bsz x n_heads x N x N
# input head_mask has shape [num_heads] or [num_hidden_layers x num_heads]
# and head_mask is converted to shape [num_hidden_layers x batch x num_heads x seq_length x seq_length]
head_mask = self.get_head_mask(head_mask, self.config.num_hidden_layers)
embedding_output = self.embeddings(flattened_patches)
encoder_outputs = self.encoder(
embedding_output,
attention_mask=attention_mask,
head_mask=head_mask,
output_attentions=output_attentions,
output_hidden_states=output_hidden_states,
return_dict=return_dict,
)
sequence_output = encoder_outputs[0]
sequence_output = self.layernorm(sequence_output)
if not return_dict:
head_outputs = (sequence_output,)
return head_outputs + encoder_outputs[1:]
return BaseModelOutput(
last_hidden_state=sequence_output,
hidden_states=encoder_outputs.hidden_states,
attentions=encoder_outputs.attentions,
)
# Copied from transformers.models.t5.modeling_t5.T5DenseGatedActDense with T5->Pix2StructText,d_model->hidden_size
class Pix2StructTextDenseGatedActDense(nn.Module):
def __init__(self, config: Pix2StructTextConfig):
super().__init__()
self.wi_0 = nn.Linear(config.hidden_size, config.d_ff, bias=False)
self.wi_1 = nn.Linear(config.hidden_size, config.d_ff, bias=False)
self.wo = nn.Linear(config.d_ff, config.hidden_size, bias=False)
self.dropout = nn.Dropout(config.dropout_rate)
self.act = ACT2FN[config.dense_act_fn]
def forward(self, hidden_states):
hidden_gelu = self.act(self.wi_0(hidden_states))
hidden_linear = self.wi_1(hidden_states)
hidden_states = hidden_gelu * hidden_linear
hidden_states = self.dropout(hidden_states)
# To make 8bit quantization work for google/flan-t5-xxl, self.wo is kept in float32.
# See https://github.com/huggingface/transformers/issues/20287
# we also make sure the weights are not in `int8` in case users will force `_keep_in_fp32_modules` to be `None``
if (
isinstance(self.wo.weight, torch.Tensor)
and hidden_states.dtype != self.wo.weight.dtype
and self.wo.weight.dtype != torch.int8
):
hidden_states = hidden_states.to(self.wo.weight.dtype)
hidden_states = self.wo(hidden_states)
return hidden_states
class Pix2StructTextLayerFF(nn.Module):
def __init__(self, config: Pix2StructTextConfig):
super().__init__()
self.DenseReluDense = Pix2StructTextDenseGatedActDense(config)
self.layer_norm = Pix2StructLayerNorm(config.hidden_size, eps=config.layer_norm_epsilon)
self.dropout = nn.Dropout(config.dropout_rate)
# Copied from transformers.models.t5.modeling_t5.T5LayerFF.forward
def forward(self, hidden_states):
forwarded_states = self.layer_norm(hidden_states)
forwarded_states = self.DenseReluDense(forwarded_states)
hidden_states = hidden_states + self.dropout(forwarded_states)
return hidden_states
class Pix2StructTextAttention(nn.Module):
def __init__(
self, config: Pix2StructTextConfig, has_relative_attention_bias=False, layer_idx: Optional[int] = None
):
super().__init__()
self.has_relative_attention_bias = has_relative_attention_bias
self.relative_attention_num_buckets = config.relative_attention_num_buckets
self.relative_attention_max_distance = config.relative_attention_max_distance
self.hidden_size = config.hidden_size
self.key_value_proj_dim = config.d_kv
self.n_heads = config.num_heads
self.dropout = config.dropout_rate
self.inner_dim = self.n_heads * self.key_value_proj_dim
self.layer_idx = layer_idx
if layer_idx is None:
logger.warning_once(
f"Instantiating a decoder {self.__class__.__name__} without passing `layer_idx` is not recommended and "
"will to errors during the forward call, if caching is used. Please make sure to provide a `layer_idx` "
"when creating this class."
)
# Mesh TensorFlow initialization to avoid scaling before softmax
self.query = nn.Linear(self.hidden_size, self.hidden_size, bias=False)
self.key = nn.Linear(self.hidden_size, self.hidden_size, bias=False)
self.value = nn.Linear(self.hidden_size, self.hidden_size, bias=False)
self.output = nn.Linear(self.hidden_size, self.hidden_size, bias=False)
if self.has_relative_attention_bias:
self.relative_attention_bias = nn.Embedding(self.relative_attention_num_buckets, self.n_heads)
self.pruned_heads = set()
self.gradient_checkpointing = False
@staticmethod
# Copied from transformers.models.t5.modeling_t5.T5Attention._relative_position_bucket
def _relative_position_bucket(relative_position, bidirectional=True, num_buckets=32, max_distance=128):
"""
Adapted from Mesh Tensorflow:
https://github.com/tensorflow/mesh/blob/0cb87fe07da627bf0b7e60475d59f95ed6b5be3d/mesh_tensorflow/transformer/transformer_layers.py#L593
Translate relative position to a bucket number for relative attention. The relative position is defined as
memory_position - query_position, i.e. the distance in tokens from the attending position to the attended-to
position. If bidirectional=False, then positive relative positions are invalid. We use smaller buckets for
small absolute relative_position and larger buckets for larger absolute relative_positions. All relative
positions >=max_distance map to the same bucket. All relative positions <=-max_distance map to the same bucket.
This should allow for more graceful generalization to longer sequences than the model has been trained on
Args:
relative_position: an int32 Tensor
bidirectional: a boolean - whether the attention is bidirectional
num_buckets: an integer
max_distance: an integer
Returns:
a Tensor with the same shape as relative_position, containing int32 values in the range [0, num_buckets)
"""
relative_buckets = 0
if bidirectional:
num_buckets //= 2
relative_buckets += (relative_position > 0).to(torch.long) * num_buckets
relative_position = torch.abs(relative_position)
else:
relative_position = -torch.min(relative_position, torch.zeros_like(relative_position))
# now relative_position is in the range [0, inf)
# half of the buckets are for exact increments in positions
max_exact = num_buckets // 2
is_small = relative_position < max_exact
# The other half of the buckets are for logarithmically bigger bins in positions up to max_distance
relative_position_if_large = max_exact + (
torch.log(relative_position.float() / max_exact)
/ math.log(max_distance / max_exact)
* (num_buckets - max_exact)
).to(torch.long)
relative_position_if_large = torch.min(
relative_position_if_large, torch.full_like(relative_position_if_large, num_buckets - 1)
)
relative_buckets += torch.where(is_small, relative_position, relative_position_if_large)
return relative_buckets
# Adapted from transformers.models.t5.modeling_t5.T5Attention.compute_bias
def compute_bias(self, query_length, key_length, device=None, cache_position=None):
"""Compute binned relative position bias"""
if device is None:
device = self.relative_attention_bias.weight.device
if cache_position is None:
context_position = torch.arange(query_length, dtype=torch.long, device=device)[:, None]
else:
context_position = cache_position[:, None].to(device)
memory_position = torch.arange(key_length, dtype=torch.long, device=device)[None, :]
relative_position = memory_position - context_position # shape (query_length, key_length)
relative_position_bucket = self._relative_position_bucket(
relative_position, # shape (query_length, key_length)
bidirectional=False,
num_buckets=self.relative_attention_num_buckets,
max_distance=self.relative_attention_max_distance,
)
values = self.relative_attention_bias(relative_position_bucket) # shape (query_length, key_length, num_heads)
values = values.permute([2, 0, 1]).unsqueeze(0) # shape (1, num_heads, query_length, key_length)
return values
# Adapted from transformers.models.t5.modeling_t5.T5Attention.forward
def forward(
self,
hidden_states,
mask=None,
key_value_states=None,
position_bias=None,
past_key_value=None,
layer_head_mask=None,
query_length=None,
use_cache=False,
output_attentions=False,
cache_position=None,
):
"""
Self-attention (if key_value_states is None) or attention over source sentence (provided by key_value_states).
"""
# Input is (batch_size, seq_length, dim)
# Mask is (batch_size, 1, 1, key_length) (non-causal) or (batch_size, 1, seq_length, key_length) (causal decoder)
batch_size, seq_length = hidden_states.shape[:2]
# if key_value_states are provided this layer is used as a cross-attention layer for the decoder
is_cross_attention = key_value_states is not None
query_states = self.query(hidden_states)
query_states = query_states.view(batch_size, -1, self.n_heads, self.key_value_proj_dim).transpose(1, 2)
# Check is encoder-decoder model is being used. Otherwise we'll get `DynamicCache`
if past_key_value is not None and isinstance(past_key_value, EncoderDecoderCache):
is_updated = past_key_value.is_updated.get(self.layer_idx)
if is_cross_attention:
# after the first generated id, we can subsequently re-use all key/value_states from cache
curr_past_key_value = past_key_value.cross_attention_cache
else:
curr_past_key_value = past_key_value.self_attention_cache
else:
curr_past_key_value = past_key_value
current_states = key_value_states if is_cross_attention else hidden_states
if is_cross_attention and past_key_value and is_updated:
# reuse k,v, cross_attentions
key_states = curr_past_key_value.layers[self.layer_idx].keys
value_states = curr_past_key_value.layers[self.layer_idx].values
else:
key_states = self.key(current_states)
value_states = self.value(current_states)
key_states = key_states.view(batch_size, -1, self.n_heads, self.key_value_proj_dim).transpose(1, 2)
value_states = value_states.view(batch_size, -1, self.n_heads, self.key_value_proj_dim).transpose(1, 2)
if past_key_value is not None:
# save all key/value_states to cache to be re-used for fast auto-regressive generation
cache_position = cache_position if not is_cross_attention else None
key_states, value_states = curr_past_key_value.update(
key_states, value_states, self.layer_idx, {"cache_position": cache_position}
)
# set flag that curr layer for cross-attn is already updated so we can re-use in subsequent calls
if is_cross_attention:
past_key_value.is_updated[self.layer_idx] = True
# compute scores, equivalent of torch.einsum("bnqd,bnkd->bnqk", query_states, key_states), compatible with onnx op>9
scores = torch.matmul(query_states, key_states.transpose(3, 2))
if position_bias is None:
key_length = key_states.shape[-2]
# cache position is 0-indexed so we add 1 to get the real length of queries (aka with past)
real_seq_length = query_length if query_length is not None else cache_position[-1] + 1
if not self.has_relative_attention_bias:
position_bias = torch.zeros(
(1, self.n_heads, seq_length, key_length), device=scores.device, dtype=scores.dtype
)
if self.gradient_checkpointing and self.training:
position_bias.requires_grad = True
else:
position_bias = self.compute_bias(
real_seq_length, key_length, device=scores.device, cache_position=cache_position
)
position_bias = position_bias[:, :, -seq_length:, :]
if mask is not None:
causal_mask = mask[:, :, :, : key_states.shape[-2]]
position_bias = position_bias + causal_mask
if self.pruned_heads:
mask = torch.ones(position_bias.shape[1])
mask[list(self.pruned_heads)] = 0
position_bias_masked = position_bias[:, mask.bool()]
else:
position_bias_masked = position_bias
scores += position_bias_masked
# (batch_size, n_heads, seq_length, key_length)
attn_weights = nn.functional.softmax(scores.float(), dim=-1).type_as(scores)
attn_weights = nn.functional.dropout(attn_weights, p=self.dropout, training=self.training)
# Mask heads if we want to
if layer_head_mask is not None:
attn_weights = attn_weights * layer_head_mask
attn_output = torch.matmul(attn_weights, value_states)
attn_output = attn_output.transpose(1, 2).contiguous()
attn_output = attn_output.view(batch_size, -1, self.inner_dim)
attn_output = self.output(attn_output)
outputs = (attn_output, position_bias)
if output_attentions:
outputs = outputs + (attn_weights,)
return outputs
# Copied from transformers.models.t5.modeling_t5.T5LayerSelfAttention with T5LayerNorm->Pix2StructLayerNorm,T5Attention->Pix2StructTextAttention,T5LayerSelfAttention->Pix2StructTextLayerSelfAttention,self.SelfAttention->self.attention,config.d_model->config.hidden_size
class Pix2StructTextLayerSelfAttention(nn.Module):
def __init__(self, config, has_relative_attention_bias=False, layer_idx: Optional[int] = None):
super().__init__()
self.attention = Pix2StructTextAttention(
config, has_relative_attention_bias=has_relative_attention_bias, layer_idx=layer_idx
)
self.layer_norm = Pix2StructLayerNorm(config.hidden_size, eps=config.layer_norm_epsilon)
self.dropout = nn.Dropout(config.dropout_rate)
def forward(
self,
hidden_states,
attention_mask=None,
position_bias=None,
layer_head_mask=None,
past_key_value=None,
use_cache=False,
output_attentions=False,
cache_position=None,
):
normed_hidden_states = self.layer_norm(hidden_states)
attention_output = self.attention(
normed_hidden_states,
mask=attention_mask,
position_bias=position_bias,
layer_head_mask=layer_head_mask,
past_key_value=past_key_value,
use_cache=use_cache,
output_attentions=output_attentions,
cache_position=cache_position,
)
hidden_states = hidden_states + self.dropout(attention_output[0])
outputs = (hidden_states,) + attention_output[1:] # add attentions if we output them
return outputs
# Copied from transformers.models.t5.modeling_t5.T5LayerCrossAttention with T5LayerNorm->Pix2StructLayerNorm,T5Attention->Pix2StructTextAttention,T5LayerCrossAttention->Pix2StructTextLayerCrossAttention,self.EncDecAttention->self.attention,config.d_model->config.hidden_size
class Pix2StructTextLayerCrossAttention(nn.Module):
def __init__(self, config, layer_idx: Optional[int] = None):
super().__init__()
self.attention = Pix2StructTextAttention(config, has_relative_attention_bias=False, layer_idx=layer_idx)
self.layer_norm = Pix2StructLayerNorm(config.hidden_size, eps=config.layer_norm_epsilon)
self.dropout = nn.Dropout(config.dropout_rate)
def forward(
self,
hidden_states,
key_value_states,
attention_mask=None,
position_bias=None,
layer_head_mask=None,
past_key_value=None,
use_cache=False,
query_length=None,
output_attentions=False,
cache_position=None,
):
normed_hidden_states = self.layer_norm(hidden_states)
attention_output = self.attention(
normed_hidden_states,
mask=attention_mask,
key_value_states=key_value_states,
position_bias=position_bias,
layer_head_mask=layer_head_mask,
past_key_value=past_key_value,
use_cache=use_cache,
query_length=query_length,
output_attentions=output_attentions,
cache_position=cache_position,
)
layer_output = hidden_states + self.dropout(attention_output[0])
outputs = (layer_output,) + attention_output[1:] # add attentions if we output them
return outputs
class Pix2StructTextBlock(GradientCheckpointingLayer):
def __init__(self, config, has_relative_attention_bias=False, layer_idx: Optional[int] = None):
super().__init__()
self.self_attention = Pix2StructTextLayerSelfAttention(
config,
has_relative_attention_bias=has_relative_attention_bias,
layer_idx=layer_idx,
)
self.encoder_decoder_attention = Pix2StructTextLayerCrossAttention(
config,
layer_idx=layer_idx,
)
self.mlp = Pix2StructTextLayerFF(config)
def forward(
self,
hidden_states,
attention_mask=None,
position_bias=None,
encoder_hidden_states=None,
encoder_attention_mask=None,
encoder_decoder_position_bias=None,
layer_head_mask=None,
cross_attn_layer_head_mask=None,
past_key_value=None,
use_cache=False,
output_attentions=False,
return_dict=True,
cache_position=None,
):
self_attention_outputs = self.self_attention(
hidden_states,
attention_mask=attention_mask,
position_bias=position_bias,
layer_head_mask=layer_head_mask,
past_key_value=past_key_value,
use_cache=use_cache,
output_attentions=output_attentions,
cache_position=cache_position,
)
hidden_states = self_attention_outputs[0]
attention_outputs = self_attention_outputs[1:] # Keep self-attention outputs and relative position weights
# clamp inf values to enable fp16 training
if hidden_states.dtype == torch.float16 and torch.isinf(hidden_states).any():
clamp_value = torch.finfo(hidden_states.dtype).max - 1000
hidden_states = torch.clamp(hidden_states, min=-clamp_value, max=clamp_value)
do_cross_attention = encoder_hidden_states is not None
if do_cross_attention:
cross_attention_outputs = self.encoder_decoder_attention(
hidden_states,
key_value_states=encoder_hidden_states,
attention_mask=encoder_attention_mask,
position_bias=encoder_decoder_position_bias,
layer_head_mask=cross_attn_layer_head_mask,
past_key_value=past_key_value,
query_length=cache_position[-1] + 1,
use_cache=use_cache,
output_attentions=output_attentions,
)
hidden_states = cross_attention_outputs[0]
# clamp inf values to enable fp16 training
if hidden_states.dtype == torch.float16 and torch.isinf(hidden_states).any():
clamp_value = torch.finfo(hidden_states.dtype).max - 1000
hidden_states = torch.clamp(hidden_states, min=-clamp_value, max=clamp_value)
# Keep cross-attention outputs and relative position weights
attention_outputs = attention_outputs + cross_attention_outputs[1:]
# Apply Feed Forward layer
hidden_states = self.mlp(hidden_states)
# clamp inf values to enable fp16 training
if hidden_states.dtype == torch.float16 and torch.isinf(hidden_states).any():
clamp_value = torch.finfo(hidden_states.dtype).max - 1000
hidden_states = torch.clamp(hidden_states, min=-clamp_value, max=clamp_value)
outputs = (hidden_states,)
return outputs + attention_outputs
@auto_docstring(
custom_intro="""
The standalone text decoder of Pix2Struct
"""
)
class Pix2StructTextModel(Pix2StructPreTrainedModel):
config: Pix2StructTextConfig
_no_split_modules = ["Pix2StructTextBlock"]
_tied_weights_keys = ["lm_head.weight"]
supports_gradient_checkpointing = True
def __init__(self, config):
super().__init__(config)
self.embed_tokens = nn.Embedding(config.vocab_size, config.hidden_size)
self.layer = nn.ModuleList(
[
Pix2StructTextBlock(config, has_relative_attention_bias=bool(i == 0), layer_idx=i)
for i in range(config.num_layers)
]
)
self.final_layer_norm = Pix2StructLayerNorm(config.hidden_size, eps=config.layer_norm_epsilon)
self.dropout = nn.Dropout(config.dropout_rate)
self.lm_head = nn.Linear(config.hidden_size, config.vocab_size, bias=False)
# Initialize weights and apply final processing
self.post_init()
self.gradient_checkpointing = False
def set_input_embeddings(self, new_embeddings):
self.embed_tokens = new_embeddings
@auto_docstring
def forward(
self,
input_ids: Optional[torch.LongTensor] = None,
attention_mask: Optional[torch.FloatTensor] = None,
encoder_hidden_states: Optional[torch.FloatTensor] = None,
encoder_attention_mask: Optional[torch.FloatTensor] = None,
inputs_embeds: Optional[torch.LongTensor] = None,
head_mask: Optional[torch.FloatTensor] = None,
cross_attn_head_mask: Optional[torch.Tensor] = None,
past_key_values: Optional[Cache] = None,
use_cache: Optional[bool] = None,
output_attentions: Optional[bool] = None,
output_hidden_states: Optional[bool] = None,
labels: Optional[torch.LongTensor] = None,
return_dict: Optional[bool] = None,
cache_position: Optional[torch.LongTensor] = None,
**kwargs,
) -> Union[tuple[torch.FloatTensor, ...], CausalLMOutputWithCrossAttentions]:
r"""
input_ids (`torch.LongTensor` of shape `(batch_size, sequence_length)`):
Indices of input sequence tokens in the vocabulary. Pix2StructText is a model with relative position
embeddings so you should be able to pad the inputs on both the right and the left.
Indices can be obtained using [`AutoTokenizer`]. See [`PreTrainedTokenizer.encode`] and
[`PreTrainedTokenizer.__call__`] for detail.
[What are input IDs?](../glossary#input-ids)
To know more on how to prepare `input_ids` for pretraining take a look a [Pix2StructText
Training](./t5#training).
cross_attn_head_mask (`torch.Tensor` of shape `(num_heads,)` or `(num_layers, num_heads)`, *optional*):
Mask to nullify selected heads of the cross-attention modules in the decoder. Mask values selected in
`[0, 1]`:
- 1 indicates the head is **not masked**,
- 0 indicates the head is **masked**.
Example:
```python
>>> from transformers import AutoProcessor, Pix2StructTextModel
>>> processor = AutoProcessor.from_pretrained("google/pix2struct-textcaps-base")
>>> model = Pix2StructTextModel.from_pretrained("google/pix2struct-textcaps-base")
>>> inputs = processor(text="Hello, my dog is cute", return_tensors="pt")
>>> outputs = model(**inputs)
>>> loss = outputs.loss
```
"""
use_cache = use_cache if use_cache is not None else self.config.use_cache
output_attentions = output_attentions if output_attentions is not None else self.config.output_attentions
output_hidden_states = (
output_hidden_states if output_hidden_states is not None else self.config.output_hidden_states
)
return_dict = return_dict if return_dict is not None else self.config.use_return_dict
if self.gradient_checkpointing and self.training and use_cache:
logger.warning(
"`use_cache=True` is incompatible with gradient checkpointing. Setting `use_cache=False`..."
)
use_cache = False
if input_ids is not None and inputs_embeds is not None:
raise ValueError("You cannot specify both decoder_input_ids and decoder_inputs_embeds at the same time")
elif input_ids is not None:
input_shape = input_ids.size()
input_ids = input_ids.view(-1, input_shape[-1])
elif inputs_embeds is not None:
input_shape = inputs_embeds.size()[:-1]
else:
raise ValueError("You have to specify either decoder_input_ids or decoder_inputs_embeds")
if inputs_embeds is None:
assert self.embed_tokens is not None, "You have to initialize the model with valid token embeddings"
inputs_embeds = self.embed_tokens(input_ids)
batch_size, seq_length = input_shape
if use_cache and past_key_values is None:
if self.config.is_encoder_decoder:
past_key_values = EncoderDecoderCache(DynamicCache(), DynamicCache())
else:
past_key_values = DynamicCache()
past_key_values_length = 0
if cache_position is not None:
past_key_values_length = cache_position[0]
elif past_key_values is not None:
past_key_values_length = past_key_values.get_seq_length()
if cache_position is None:
cache_position = torch.arange(
past_key_values_length, past_key_values_length + seq_length, device=inputs_embeds.device
)
if attention_mask is None:
# required mask seq length can be calculated via length of past
mask_seq_length = (
past_key_values.get_seq_length() + seq_length if past_key_values is not None else seq_length
)
attention_mask = torch.ones(batch_size, mask_seq_length, device=inputs_embeds.device)
if self.config.is_decoder:
causal_mask = self._update_causal_mask(
attention_mask,
inputs_embeds,
cache_position,
past_key_values.self_attention_cache
if isinstance(past_key_values, EncoderDecoderCache)
else past_key_values,
output_attentions,
)
else:
causal_mask = attention_mask[:, None, None, :]
causal_mask = causal_mask.to(dtype=inputs_embeds.dtype)
causal_mask = (1.0 - causal_mask) * torch.finfo(inputs_embeds.dtype).min
# If a 2D or 3D attention mask is provided for the cross-attention
# we need to make broadcastable to [batch_size, num_heads, seq_length, seq_length]
if encoder_hidden_states is not None:
encoder_batch_size, encoder_sequence_length, _ = encoder_hidden_states.size()
encoder_hidden_shape = (encoder_batch_size, encoder_sequence_length)
if encoder_attention_mask is None:
encoder_attention_mask = torch.ones(encoder_hidden_shape, device=inputs_embeds.device)
encoder_extended_attention_mask = self.invert_attention_mask(encoder_attention_mask)
else:
encoder_extended_attention_mask = None
# Prepare head mask if needed
head_mask = self.get_head_mask(head_mask, self.config.num_layers)
cross_attn_head_mask = self.get_head_mask(cross_attn_head_mask, self.config.num_layers)
all_hidden_states = () if output_hidden_states else None
all_attentions = () if output_attentions else None
all_cross_attentions = () if (output_attentions) else None
position_bias = None
encoder_decoder_position_bias = None
hidden_states = self.dropout(inputs_embeds)
for i, layer_module in enumerate(self.layer):
layer_head_mask = head_mask[i]
cross_attn_layer_head_mask = cross_attn_head_mask[i]
if output_hidden_states:
all_hidden_states = all_hidden_states + (hidden_states,)
layer_outputs = layer_module(
hidden_states,
causal_mask,
position_bias,
encoder_hidden_states,
encoder_extended_attention_mask,
encoder_decoder_position_bias, # as a positional argument for gradient checkpointing
layer_head_mask=layer_head_mask,
cross_attn_layer_head_mask=cross_attn_layer_head_mask,
past_key_value=past_key_values,
use_cache=use_cache,
output_attentions=output_attentions,
cache_position=cache_position,
)
hidden_states = layer_outputs[0]
# We share the position biases between the layers - the first layer store them
# layer_outputs = hidden-states, key-value-states (self-attention position bias), (self-attention weights),
# (cross-attention position bias), (cross-attention weights)
position_bias = layer_outputs[1]
if encoder_hidden_states is not None:
encoder_decoder_position_bias = layer_outputs[3 if output_attentions else 2]
if output_attentions:
all_attentions = all_attentions + (layer_outputs[2],)
if encoder_hidden_states is not None:
all_cross_attentions = all_cross_attentions + (layer_outputs[4],)
hidden_states = self.final_layer_norm(hidden_states)
hidden_states = self.dropout(hidden_states)
logits = self.lm_head(hidden_states)
# Add last layer
if output_hidden_states:
all_hidden_states = all_hidden_states + (hidden_states,)
loss = None
if labels is not None:
# move labels to correct device to enable model parallelism
labels = labels.to(logits.device)
loss_fct = nn.CrossEntropyLoss(ignore_index=-100, reduction="mean")
loss = loss_fct(logits.contiguous().view(-1, logits.size(-1)), labels.contiguous().view(-1))
if not return_dict:
return tuple(
v
for v in [
loss,
logits,
past_key_values,
all_hidden_states,
all_attentions,
all_cross_attentions,
]
if v is not None
)
return CausalLMOutputWithCrossAttentions(
loss=loss,
logits=logits,
past_key_values=past_key_values,
hidden_states=all_hidden_states,
attentions=all_attentions,
cross_attentions=all_cross_attentions,
)
# Copied from transformers.models.gptj.modeling_gptj.GPTJModel._update_causal_mask
def _update_causal_mask(
self,
attention_mask: Union[torch.Tensor, "BlockMask"],
input_tensor: torch.Tensor,
cache_position: torch.Tensor,
past_key_values: Cache,
output_attentions: bool = False,
):
if self.config._attn_implementation == "flash_attention_2":
if attention_mask is not None and (attention_mask == 0.0).any():
return attention_mask
return None
if self.config._attn_implementation == "flex_attention":
if isinstance(attention_mask, torch.Tensor):
attention_mask = make_flex_block_causal_mask(attention_mask)
return attention_mask
# For SDPA, when possible, we will rely on its `is_causal` argument instead of its `attn_mask` argument, in
# order to dispatch on Flash Attention 2. This feature is not compatible with static cache, as SDPA will fail
# to infer the attention mask.
past_seen_tokens = past_key_values.get_seq_length() if past_key_values is not None else 0
using_compilable_cache = past_key_values.is_compileable if past_key_values is not None else False
# When output attentions is True, sdpa implementation's forward method calls the eager implementation's forward
if self.config._attn_implementation == "sdpa" and not using_compilable_cache and not output_attentions:
if AttentionMaskConverter._ignore_causal_mask_sdpa(
attention_mask,
inputs_embeds=input_tensor,
past_key_values_length=past_seen_tokens,
is_training=self.training,
):
return None
dtype = input_tensor.dtype
sequence_length = input_tensor.shape[1]
if using_compilable_cache:
target_length = past_key_values.get_max_cache_shape()
else:
target_length = (
attention_mask.shape[-1]
if isinstance(attention_mask, torch.Tensor)
else past_seen_tokens + sequence_length + 1
)
# In case the provided `attention` mask is 2D, we generate a causal mask here (4D).
causal_mask = self._prepare_4d_causal_attention_mask_with_cache_position(
attention_mask,
sequence_length=sequence_length,
target_length=target_length,
dtype=dtype,
cache_position=cache_position,
batch_size=input_tensor.shape[0],
)
if (
self.config._attn_implementation == "sdpa"
and attention_mask is not None
and attention_mask.device.type in ["cuda", "xpu", "npu"]
and not output_attentions
):
# Attend to all tokens in fully masked rows in the causal_mask, for example the relevant first rows when
# using left padding. This is required by F.scaled_dot_product_attention memory-efficient attention path.
# Details: https://github.com/pytorch/pytorch/issues/110213
min_dtype = torch.finfo(dtype).min
causal_mask = AttentionMaskConverter._unmask_unattended(causal_mask, min_dtype)
return causal_mask
@staticmethod
# Copied from transformers.models.gptj.modeling_gptj.GPTJModel._prepare_4d_causal_attention_mask_with_cache_position
def _prepare_4d_causal_attention_mask_with_cache_position(
attention_mask: torch.Tensor,
sequence_length: int,
target_length: int,
dtype: torch.dtype,
cache_position: torch.Tensor,
batch_size: int,
**kwargs,
):
"""
Creates a causal 4D mask of shape `(batch_size, 1, query_length, key_value_length)` from a 2D mask of shape
`(batch_size, key_value_length)`, or if the input `attention_mask` is already 4D, do nothing.
Args:
attention_mask (`torch.Tensor`):
A 2D attention mask of shape `(batch_size, key_value_length)` or a 4D attention mask of shape
`(batch_size, 1, query_length, key_value_length)`.
sequence_length (`int`):
The sequence length being processed.
target_length (`int`):
The target length: when generating with static cache, the mask should be as long as the static cache,
to account for the 0 padding, the part of the cache that is not filled yet.
dtype (`torch.dtype`):
The dtype to use for the 4D attention mask.
cache_position (`torch.Tensor`):
Indices depicting the position of the input sequence tokens in the sequence.
batch_size (`torch.Tensor`):
Batch size.
"""
if attention_mask is not None and attention_mask.dim() == 4:
# In this case we assume that the mask comes already in inverted form and requires no inversion or slicing.
causal_mask = attention_mask
else:
min_dtype = torch.finfo(dtype).min
causal_mask = torch.full(
(sequence_length, target_length), fill_value=min_dtype, dtype=dtype, device=cache_position.device
)
if sequence_length != 1:
causal_mask = torch.triu(causal_mask, diagonal=1)
causal_mask *= torch.arange(target_length, device=cache_position.device) > cache_position.reshape(-1, 1)
causal_mask = causal_mask[None, None, :, :].expand(batch_size, 1, -1, -1)
if attention_mask is not None:
causal_mask = causal_mask.clone() # copy to contiguous memory for in-place edit
mask_length = attention_mask.shape[-1]
padding_mask = causal_mask[:, :, :, :mask_length] + attention_mask[:, None, None, :].to(
causal_mask.device
)
padding_mask = padding_mask == 0
causal_mask[:, :, :, :mask_length] = causal_mask[:, :, :, :mask_length].masked_fill(
padding_mask, min_dtype
)
return causal_mask
@auto_docstring(
custom_intro="""
A conditional generation model with a language modeling head. Can be used for sequence generation tasks.
"""
)
class Pix2StructForConditionalGeneration(Pix2StructPreTrainedModel, GenerationMixin):
config: Pix2StructConfig
main_input_name = "flattened_patches"
_tied_weights_keys = ["decoder.lm_head.weight"]
def __init__(self, config: Pix2StructConfig):
super().__init__(config)
self.encoder = Pix2StructVisionModel(config.vision_config)
self.decoder = Pix2StructTextModel(config.text_config)
self.is_vqa = config.is_vqa
# Initialize weights and apply final processing
self.post_init()
def get_input_embeddings(self):
return self.decoder.get_input_embeddings()
def set_input_embeddings(self, new_embeddings):
self.decoder.set_input_embeddings(new_embeddings)
def get_output_embeddings(self) -> nn.Module:
return self.decoder.get_output_embeddings()
def set_output_embeddings(self, new_embeddings):
self.decoder.set_output_embeddings(new_embeddings)
def get_decoder(self):
return self.decoder
def get_encoder(self):
return self.encoder
@auto_docstring
def forward(
self,
flattened_patches: Optional[torch.FloatTensor] = None,
attention_mask: Optional[torch.FloatTensor] = None,
decoder_input_ids: Optional[torch.LongTensor] = None,
decoder_attention_mask: Optional[torch.BoolTensor] = None,
head_mask: Optional[torch.FloatTensor] = None,
decoder_head_mask: Optional[torch.FloatTensor] = None,
cross_attn_head_mask: Optional[torch.Tensor] = None,
encoder_outputs: Optional[tuple[tuple[torch.FloatTensor]]] = None,
past_key_values: Optional[Cache] = None,
labels: Optional[torch.LongTensor] = None,
decoder_inputs_embeds: Optional[torch.Tensor] = None,
use_cache: Optional[bool] = None,
output_attentions: Optional[bool] = None,
output_hidden_states: Optional[bool] = None,
return_dict: Optional[bool] = None,
cache_position: Optional[torch.LongTensor] = None,
) -> Union[tuple[torch.FloatTensor], Seq2SeqModelOutput]:
r"""
flattened_patches (`torch.FloatTensor` of shape `(batch_size, seq_length, hidden_size)`):
Flattened pixel patches. the `hidden_size` is obtained by the following formula: `hidden_size` =
`num_channels` * `patch_size` * `patch_size`
The process of flattening the pixel patches is done by `Pix2StructProcessor`.
decoder_input_ids (`torch.LongTensor` of shape `(batch_size, target_sequence_length)`, *optional*):
Indices of decoder input sequence tokens in the vocabulary.
Indices can be obtained using [`AutoTokenizer`]. See [`PreTrainedTokenizer.encode`] and
[`PreTrainedTokenizer.__call__`] for details.
[What are decoder input IDs?](../glossary#decoder-input-ids)
Pix2StructText uses the `pad_token_id` as the starting token for `decoder_input_ids` generation. If
`past_key_values` is used, optionally only the last `decoder_input_ids` have to be input (see
`past_key_values`).
To know more on how to prepare `decoder_input_ids` for pretraining take a look at [Pix2StructText
Training](./t5#training).
decoder_attention_mask (`torch.BoolTensor` of shape `(batch_size, target_sequence_length)`, *optional*):
Default behavior: generate a tensor that ignores pad tokens in `decoder_input_ids`. Causal mask will also
be used by default.
decoder_head_mask (`torch.FloatTensor` of shape `(num_heads,)` or `(num_layers, num_heads)`, *optional*):
Mask to nullify selected heads of the self-attention modules in the decoder. Mask values selected in `[0,
1]`:
- 1 indicates the head is **not masked**,
- 0 indicates the head is **masked**.
cross_attn_head_mask (`torch.Tensor` of shape `(num_heads,)` or `(num_layers, num_heads)`, *optional*):
Mask to nullify selected heads of the cross-attention modules in the decoder. Mask values selected in
`[0, 1]`:
- 1 indicates the head is **not masked**,
- 0 indicates the head is **masked**.
labels (`torch.LongTensor` of shape `(batch_size, sequence_length)`, *optional*):
Labels for computing the masked language modeling loss for the decoder.
Example:
Inference:
```python
>>> from PIL import Image
>>> import requests
>>> from transformers import AutoProcessor, Pix2StructForConditionalGeneration
>>> processor = AutoProcessor.from_pretrained("google/pix2struct-textcaps-base")
>>> model = Pix2StructForConditionalGeneration.from_pretrained("google/pix2struct-textcaps-base")
>>> url = "https://www.ilankelman.org/stopsigns/australia.jpg"
>>> image = Image.open(requests.get(url, stream=True).raw)
>>> inputs = processor(images=image, return_tensors="pt")
>>> # autoregressive generation
>>> generated_ids = model.generate(**inputs, max_new_tokens=50)
>>> generated_text = processor.batch_decode(generated_ids, skip_special_tokens=True)[0]
>>> print(generated_text)
A stop sign is on a street corner.
>>> # conditional generation
>>> text = "A picture of"
>>> inputs = processor(text=text, images=image, return_tensors="pt", add_special_tokens=False)
>>> generated_ids = model.generate(**inputs, max_new_tokens=50)
>>> generated_text = processor.batch_decode(generated_ids, skip_special_tokens=True)[0]
>>> print(generated_text)
A picture of a stop sign with a red stop sign
```
Training:
```python
>>> from PIL import Image
>>> import requests
>>> from transformers import AutoProcessor, Pix2StructForConditionalGeneration
>>> processor = AutoProcessor.from_pretrained("google/pix2struct-base")
>>> model = Pix2StructForConditionalGeneration.from_pretrained("google/pix2struct-base")
>>> url = "https://www.ilankelman.org/stopsigns/australia.jpg"
>>> image = Image.open(requests.get(url, stream=True).raw)
>>> text = "A stop sign is on the street corner."
>>> inputs = processor(images=image, return_tensors="pt")
>>> labels = processor(text=text, return_tensors="pt").input_ids
>>> # forward pass
>>> outputs = model(**inputs, labels=labels)
>>> loss = outputs.loss
>>> print(f"{loss.item():.5f}")
5.94282
```"""
use_cache = use_cache if use_cache is not None else self.config.text_config.use_cache
return_dict = return_dict if return_dict is not None else self.config.use_return_dict
# Encode if needed (training, first prediction pass)
if encoder_outputs is None:
encoder_outputs = self.encoder(
flattened_patches=flattened_patches,
attention_mask=attention_mask,
head_mask=head_mask,
output_attentions=output_attentions,
output_hidden_states=output_hidden_states,
return_dict=return_dict,
)
elif return_dict and not isinstance(encoder_outputs, BaseModelOutput):
encoder_outputs = BaseModelOutput(
last_hidden_state=encoder_outputs[0],
hidden_states=encoder_outputs[1] if len(encoder_outputs) > 1 else None,
attentions=encoder_outputs[2] if len(encoder_outputs) > 2 else None,
)
hidden_states = encoder_outputs[0]
if labels is not None and decoder_input_ids is None and decoder_inputs_embeds is None:
# get decoder inputs from shifting lm labels to the right
decoder_input_ids = self._shift_right(labels)
decoder_attention_mask = (
decoder_attention_mask
if decoder_attention_mask is not None
else decoder_input_ids.ne(self.config.pad_token_id).float()
)
# Always attend to the first token
decoder_attention_mask[:, 0] = 1
# Decode
decoder_outputs = self.decoder(
input_ids=decoder_input_ids,
attention_mask=decoder_attention_mask,
inputs_embeds=decoder_inputs_embeds,
past_key_values=past_key_values,
encoder_hidden_states=hidden_states,
encoder_attention_mask=attention_mask,
head_mask=decoder_head_mask,
cross_attn_head_mask=cross_attn_head_mask,
use_cache=use_cache,
output_attentions=output_attentions,
output_hidden_states=output_hidden_states,
labels=labels,
return_dict=return_dict,
cache_position=cache_position,
)
if not return_dict:
return decoder_outputs + encoder_outputs
return Seq2SeqLMOutput(
loss=decoder_outputs.loss,
logits=decoder_outputs.logits,
past_key_values=decoder_outputs.past_key_values,
decoder_hidden_states=decoder_outputs.hidden_states,
decoder_attentions=decoder_outputs.attentions,
cross_attentions=decoder_outputs.cross_attentions,
encoder_last_hidden_state=encoder_outputs.last_hidden_state,
encoder_hidden_states=encoder_outputs.hidden_states,
encoder_attentions=encoder_outputs.attentions,
)
__all__ = [
"Pix2StructPreTrainedModel",
"Pix2StructForConditionalGeneration",
"Pix2StructVisionModel",
"Pix2StructTextModel",
]